Leg amputee support assembly for use with a wheelchair

ABSTRACT

An amputee support assembly includes a seat, a limb support and a pivot point disposed between the seat and limb support. The seat is attached to a first pivot member, a second pivot member, and a cam lock mechanism. The first pivot member and the second pivot member are adapted to rotatably engage one another when the cam lock mechanism is used. Each pivot member includes a hub portion having a circular face and a number of teeth defined within the face. The first pivot member includes a hub recess that is designed to receive a hub extension of the second pivot member. The outer periphery of the hub portion of the second pivot member also includes a lip that precludes access to the teeth that lie between the first and second pivot members. The cam lock mechanism includes a cam lock lever that is pivotally attached to a lock post. Rotation of the cam lock lever effects a pulling force on the lock post, forcing the pivot members together to prevent rotation between them. The second pivot member is attached to the limb support.

FIELD OF THE INVENTION

This invention relates generally to wheelchairs and to accessory itemsand assemblies for use with wheelchairs. More particularly, it relatesto a leg amputee support assembly that can be easily used with awheelchair for quickly and easily adjusting the support position of anamputee wheelchair user's residual leg portion. It also relates to a legamputee support assembly that can be removed from the wheelchair for usewith chairs or other seating devices.

BACKGROUND OF THE INVENTION

Conventional wheelchairs are normally equipped with a main tubular framehaving a seat and two generally upright support members located to therear of the wheelchair seat and adjacent the user's back. Conventionalwheelchairs also have two generally upright support members located tothe front of the wheelchair. These supports are typically used toprovide footrests for wheelchair users. In the experience of thisinventor, however, there is also a need to provide quick and versatilemovement for the comfortable positioning of limb stumps in the case of awheelchair user who also happens to be a leg amputee. There is also aneed for a support that is infinitely adjustable between a wide varietyof angles to provide for the comfort of the wheelchair occupant.Additionally, there is need for a leg support that can be quickly andeasily moved out of the way to allow the user to transfer in and out ofthe wheelchair without being encumbered by the leg support. Furthermore,there is a need for an easy way to accomplish such versatile movementwithout cumbersome equipment and complicated steps.

SUMMARY OF THE INVENTION

It is, therefore a principal object of the present invention to providea new, useful, and uncomplicated assembly for a variably adjustablesupport for the residual leg of an amputee wheelchair user. It is afurther object of this invention to provide such an assembly whereby theuser can adjust the limb position by a simple release of a lever. It isalso an object of this invention to provide such an assembly thatrequires only a minimal number of elements and a minimal number of stepsto utilize. It is yet another object of this invention to provide suchan assembly that can readily be used by a wide variety of wheelchairoccupants, including those having upper body weakness. It is stillanother object of this invention to provide such an assembly that isreadily and quickly adjustable so as to accommodate the many shapes andsizes of persons needing to use the wheelchair that is equipped with theassembly of the present invention. It is an additional object to providean assembly that can be quickly and easily moved out of the way of thewheelchair occupant to facilitate transfers in and out of thewheelchair. And it is yet another object of this invention to providesuch an assembly that can be used with chairs and seating devices otherthan wheelchairs.

The present invention has obtained these objects. It provides for anamputee support assembly that includes a seat, a limb support and apivot point assembly disposed between the seat and the limb support. Theseat is attached to a first pivot member, a second pivot member, and acam lock mechanism. The first pivot member and the second pivot memberare adapted to movably engage one another when the cam lock mechanism isused. Each pivot member includes a hub portion having a circular faceand a number of teeth defined within the face. The first pivot memberincludes a hub recess that is designed to receive a hub extension of thesecond pivot member. The outer periphery of the hub portion of thesecond pivot member also includes a lip that precludes access to theteeth that lie between the first and second pivot members. The cam lockmechanism includes a cam lock lever that is pivotally attached to a lockpost. Rotation of the cam lock lever effects a pulling force on the lockpost which forces the first and second pivot members securely togetherto prevent rotation between them. In this fashion, the cam lockmechanism can be locked and unlocked to secure or allow movement betweenthe two pivot members. When a desired position is found by thewheelchair user, the cam lock lever can be urged downwardly toward thesecond pivot member. This will rotate a cam portion of the cam locklever thereby exerting a tension force on the lock bolt and urging themeshed teeth of the pivot members together and preventing movementbetween them. This position will be maintained until a change ofposition is desired or required by the wheelchair user. The foregoingand other features of the assembly of the present invention will beapparent from the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front, top and right side perspective view of a conventionalwheelchair that includes an amputee support assembly constructed inaccordance with the present invention.

FIG. 2 is an enlarged side elevational view of the cam lock portion ofthe amputee support assembly shown in FIG. 1.

FIG. 3 is a top plan and cross sectioned view of the cam lock portion ofthe amputee support assembly taken along line 3-3 of FIG. 2 and showingthe cam lock in the “locked” position.

FIG. 4 is another top plan and cross sectioned view of the cam lockportion of the amputee support assembly illustrated in FIG. 3 andshowing the cam lock in the “unlocked” position.

FIG. 5 is a side elevational view of the second pivot member of theamputee support assembly taken along line 5-5 of FIG. 4.

FIG. 6 is a side elevational view of the first pivot member of theamputee support assembly taken along line 6-6 of FIG. 4.

FIG. 7 is a front elevational view of the first pivot member taken alongline 7-7 of FIG. 6.

DETAILED DESCRIPTION

The following detailed description is intended to describe the preferredembodiments that are depicted in the figures. It is to be understoodthat changes could be made to that which is specifically described andshown that would still fall within the scope of the present invention.

Referring now to the drawings in detail, wherein like numbered elementsrefer to like elements throughout, FIG. 1 illustrates a typicalwheelchair, generally identified 10, with which the assembly of thepresent invention is intended to be used. It is to be understood thatthe specific type or model of wheelchair 10 is not particularlyimportant for purposes of this detailed description. Important is thefact that the wheelchair 10 have a seat and be functionally adapted touse an amputee support assembly, generally identified 40, of the typedisclosed herein. In the view of this inventor, the limb supportassembly 40 is most efficiently used in a setting wherein the wheelchairuser is an amputee and the limb support assembly 40 is used tocomfortably support a limb stump. The versatility of movement andadjustability of the assembly 40 of the present invention makes it anideal device for such an application. It is to be understood, however,that the use of the assembly is not so limited. The assembly 40 can beused with chairs and seating devices other than wheelchairs.

Again referring to FIG. 1, the amputee support assembly 40 of thepresent invention is employed as a part of the wheelchair 10 by simplyplacing it upon the seat (not shown) of the wheelchair 10. A belt orties (not shown) may be used to secure the assembly 40 to the chair 10.The support assembly 40 generally includes a seat portion 42 and a limbsupport portion 44. Attachable to the underside of the seat portion 42is a seat portion bracket 20 having a first bracket portion 22 and asecond bracket portion 24, the first bracket portion 22 being in anessentially horizontal plane and the second bracket portion 24 being inan essentially vertical plane and forming an “L” shape. See FIG. 2. Thefirst bracket portion 22 includes a slot 23 and the second bracketportion 24 includes a slot or aperture (not shown). Fasteners 51 areused to attach the bracket 20 to the seat portion 42. Similarly,fasteners 53 are used to attach the bracket 20 to a first pivot member60. See FIG. 3.

Interposed between the seat portion 42 and the limb portion 44 is afirst pivot member 60, a second pivot member 70, and a cam lockmechanism 80. The first pivot member 60 and the second pivot member 70of the limb support assembly 40 are functionally adapted to movablyengage one another and work together to secure the position of themembers 60, 70 relative to one another when the cam lock mechanism 80 isused as intended. As shown in FIG. 6, the first pivot member 60 includesa proximal portion 62 and a distal hub portion 64. The distal hubportion 64 comprises a generally circular face having a number of teethor serrations 66 defined within the face. See FIG. 7. The distal hubportion 64 of the first pivot member 60 also includes a central hubrecess 67 and a central aperture 68. The purpose of that structure willbe apparent further in this detailed description.

The amputee limb support assembly 40 also includes a second pivot member70. The second pivot member 70 includes a proximal hub portion 72 and adistal portion 74. The proximal hub portion 72 comprises a generallycircular face having a number of teeth or serrations 76 defined withinthe face. See FIG. 5. It is this proximal hub portion 72 that isfunctionally adapted to engage the distal hub portion 64 of the firstpivot member 60. And, in actuality, it is the teeth 76 of the proximalhub portion 72 that are functionally adapted to engage the teeth 66 ofthe distal hub portion 64. The proximal hub portion 72 of the secondpivot member 70 also includes a central hub extension 77 and a centralaperture 78.

Referring again to FIGS. 3 and 4, it will be apparent that the firstpivot member 60 and the second pivot member 70 comprise profiles thatare significant in the structure of the assembly of the presentinvention. For example, the first pivot member 60 is, at its proximalportion 62, attachable to the seat bracket 20. The distal hub portion 64of the first pivot member 60 also includes a hub recess 67 as alluded toearlier. This hub recess 67 is designed to receive the hub extension 77of the proximal hub portion 72 of the second pivot member 70. See FIG.3. The outer periphery of the proximal hub portion 72 of the secondpivot member 70 also includes a lip 79. This lip 79 precludes access tothe teeth 66, 76 that lie between the first and second pivot members 60,70, respectively. It is also to be understood that the configurationdisclosed herein could be designed such that the hub portion isintegrally formed as part of the second pivot member 70 and that the hubrecess is integrally formed as part of the first pivot member 60, thelip being formed as part of the latter as well.

The limb support assembly 40 of the present invention also includes acam lock mechanism 80. As shown in FIGS. 3 and 4, the cam lock mechanism80 includes a lock post 87 having a first end 82 and a second end 84.The first end 82 of the lock post 87 is threaded and has a complementarythreaded nut 88 formed as a stop device. The second end 84 of the lockpost 87 has an aperture (note shown) defined within it. The cam lockmechanism 80 includes a cam lock lever 86 that is pivotally attached tothe second end 84 of the lock post 87 by means of a pin 52 that isinserted through a proximal end 81 of the lever 86 and through the lockpost aperture. The proximal end 81 of the cam lock lever 86 includes acam surface 89 whereby rotation of the cam lock lever 86 about the pin52 and toward the second pivot member 70 effects a pulling force on thelock post 87. A spring 85 is interposed between the first and secondpivot members 60, 70, respectively, to urge the pivot members 60, 70away from one another. When the cam lever 86 is moved to an “unlocked”position which is generally perpendicular to the second pivot member 70,the spring 85 becomes relaxed. When the cam lever 86 is moved downwardlytoward the second pivot member 70 in its “locked” position, the spring85 is under tension and secures the cam lever 86 in position. Rotationof the cam lock lever 86 is accomplished by lifting the distal end 83 ofthe lever 86 away from the second pivot member 70. It should also benoted that the cam lock lever 86 is not positionally dependent. That is,when the cam lock lever 86 is in its “unlocked” position, the cam locklever 86 can be rotated 360° about the axis formed by the lock post 87.In this fashion, the user can select the cam lock lever 86 position thatis most comfortable or useful for him or her.

The distal portion 74 of the second pivot member 70 is receivable withina receiving post 92 of the limb support 44. See FIGS. 2 and 3. Thereceiving post 92 is secured to the distal portion 74 of the secondpivot member 70 by means of a fastener 54. When used as intended, thelimb support 44 can be movable to many comfortable positions by theuser, particularly to accommodate comfortable positions where the useris an amputee.

In the application of the preferred embodiment, the amputee supportassembly 40 is simply placed onto the seat of the wheelchair 10 andsecured using the belt or ties (not shown) as previously referred to. Athis point, the limb support 44 may not be in a desired position.Accordingly, the cam lock mechanism 80 is released to allow the firstpivot member 60 and the second pivot member 70 to rotate relative to oneanother. This is accomplished by lifting the cam lock lever 86 whicheffects a release of tension on the lock post 87 thereby allowing thepivot members 60, 70 to be movable relative to one another. At thispoint, the teeth 66, 76 of the pivot members 60, 70, respectively, aredisengaged such that the pivot members 60, 70 may be rotated relative toone another. This will allow the user to change the position of the limbsupport 44. Assuming that the first pivot member 60 is held in fixedposition relative to the seat 42, rotation between the first and secondpivot members 60, 70 will be observed by the user to be the second pivotmember 70 rotating about the first pivot member 60. As shown in FIG. 2,the limb support 44 will be movable upwardly or downwardly relative tothe horizontal.

When a desired or required position is found, as determined by the user,the cam lock lever 86 will then be urged downwardly toward the secondpivot member 70. This will rotate the cam portion 89 of the proximalportion 84 of the cam lock lever 86 thereby exerting a tension force onthe lock bolt 87 and urging the meshed teeth 66, 67 of the pivot members60, 70 together and preventing movement between them. This position willbe maintained until a change of position is desired or required by thewheelchair user.

Although I have very specifically described the preferred embodiments ofthe invention herein, it is to be understood that changes can be made tothe improvements disclosed without departing from the scope of theinvention. Therefore, it is to be understood that the scope of theinvention is not to be overly limited by the specification and thedrawings, but is to be determined by the broadest possibleinterpretation of the claims.

1. An amputee support assembly for use with a wheelchair comprising aseat member, a first pivot member, a second pivot member, said secondpivot member being movable relative to the first pivot member, means forreleasably fixing the position of the first pivot member relative to thesecond pivot member, means for affixing the first pivot member to theseat member, a limb support member, and means for affixing the secondpivot member to the limb support member whereby the limb support membermay be used to support one or more limbs of a user seated in thewheelchair.
 2. The amputee support assembly of claim 1 wherein the firstpivot member includes a generally circular face portion having aplurality of teeth defined within the face portion and extendingradially outwardly from its center, the second pivot member includes agenerally circular face portion having a plurality of teeth definedwithin the face portion and extending radially outwardly from itscenter, and the means for fixing the position of the first pivot memberrelative to the second pivot member includes means for meshing the teethof the first pivot member face with the teeth of the second pivot memberface.
 3. The amputee support assembly of claim 2 wherein the first pivotmember face includes an aperture located generally within the center ofthe first pivot member face, the second pivot member face includes anaperture located generally within the center of the second pivot memberface, said face apertures being substantially aligned when the firstpivot member face is engaged with the second pivot member face, and themeans for fixing the position of the first pivot member relative to thesecond pivot member includes a cam lock mechanism that is insertablewithin the aligned apertures.
 4. The amputee support assembly of claim 3wherein the cam lock mechanism further includes a lock post that extendsthrough the aligned apertures, said lock post having a first end and asecond end, and includes a stop device at the first end and a cam leverat the second end whereby actuation of the cam lever draws the stopdevice toward the cam lever and engages the pivot member teeth toprevent rotational movement thereby.
 5. The amputee support assembly ofclaim 4 including a hub recess defined within the first pivot member anda hub extension defined within the second pivot member whereby the hubextension is receivable within the hub recess.
 6. The amputee supportassembly of claim 5 including means for preventing access to the meshingteeth of the pivot members.
 7. The amputee support assembly of claim 6wherein the access preventing means comprises a lip surrounding theouter periphery of the face portion of the second pivot member.
 8. Anamputee support assembly for use with a conventional wheelchair, saidwheelchair including a support frame and a seat, which comprises a seatmember, means for removably attaching the seat member to the wheelchairsupport frame such that the seat member of the assembly rests atop thewheelchair seat, at least one limb support member, a first pivot pointmember, a second pivot point member, said second pivot point memberbeing movable relative to the first pivot point member, means forreleasably fixing the position of the first pivot point member relativeto the second pivot point member, means for attaching the first pivotpoint member to the seat member, and means for attaching the secondpivot member to the at least one limb support member such that the angleof elevation is variably adjustable.
 9. The amputee support assembly ofclaim 8 wherein the first pivot point member includes a generallycircular face having a center and a plurality of teeth defined withinthe face and extending radially outwardly from the center, the secondpivot point member includes a generally circular face portion having acenter and a plurality of teeth defined within the face and extendingradially outwardly from the center, and the means for fixing theposition of the first pivot point member relative to the second pivotpoint member includes means for meshing the teeth of the first pivotpoint member face with the teeth of the second pivot point member face.10. The amputee support point assembly of claim 9 wherein the firstpivot point member face includes an aperture located generally withinthe center of the first pivot point member face, the second pivot pointmember face includes an aperture located generally within the center ofthe second pivot point member face, said face apertures beingsubstantially aligned when the first pivot point member face is engagedwith the second pivot point member face, and the means for fixing theposition of the first pivot point member relative to the second pivotpoint member includes a cam lock mechanism that is insertable within thealigned apertures.
 11. The amputee support assembly of claim 10 whereinthe cam lock mechanism further includes a lock post that extends throughthe aligned apertures, said lock post having a first end and a secondend, and includes a stop device at the first end and a cam lever at thesecond end whereby actuation of the cam lever draws the stop devicetoward the cam lever and engages the pivot point member teeth to preventrelative rotational movement therebetween.
 12. The amputee supportassembly of claim 11 including a hub recess defined within the firstpivot point member and a hub extension defined within the second pivotpoint member whereby the hub extension is receivable within the hubrecess.
 13. The amputee support assembly of claim 12 including means forpreventing access to the meshing teeth of the pivot point members. 14.The amputee support assembly of claim 13 wherein the access preventingmeans comprises a lip surrounding the outer periphery of the faceportion of the second pivot point member.
 15. The amputee supportassembly of claim 11 including a hub recess defined within the secondpivot point member and a hub extension defined within the first pivotpoint member whereby the hub extension is receivable within the hubrecess.
 16. The amputee support assembly of claim 15 including means forpreventing access to the meshing teeth of the pivot point members. 17.The amputee support assembly of claim 16 wherein the access preventingmeans comprises a lip surrounding the outer periphery of the faceportion of the first pivot point member.
 18. An amputee support pivotassembly for use with a conventional wheelchair that has a frame, saidwheelchair frame having a front frame portion and a rear frame portion,a backrest and a seat, which comprises a seat, a first pivot member,said first pivot member being attachable to the seat and comprising afirst pivot member bracket having a face portion, a residual limbsupport, a second pivot member, said second pivot member beingattachable to the residual limb support and comprising a second pivotmember bracket having a face portion, a set of radially disposed teethdefined within the face portion of each pivot member, said teethextending radially outwardly from a center point of the face portion,and means for engaging the teeth of the first pivot member with theteeth of the second pivot member wherein the angle of elevation of theresidual limb support is variably adjustable relative to the seat. 19.The amputee support pivot assembly of claim 18 wherein the first pivotmember face includes an aperture located generally within the center ofthe first pivot member face, the second pivot member face includes anaperture located generally within the center of the second pivot memberface, said face apertures being substantially aligned when the firstpivot member face is engaged with the second pivot member face, and theteeth engagement means includes a cam lock mechanism that is insertablewithin the aligned apertures, the cam lock mechanism further including alock post that extends through the aligned apertures, said lock posthaving a first end and a second end, and including a stop device at thefirst end and a cam lever at the second end such that actuation of thecam lever draws the stop device toward the cam lever and engages thepivot member teeth to prevent rotational movement therebetween.
 20. Theamputee support pivot assembly of claim 19 including a hub recessdefined within the first pivot member, a hub extension defined withinthe second pivot member whereby the hub extension is receivable withinthe hub recess, and a lip surrounding the outer periphery of the faceportion of the second pivot member to prevent access to the meshingteeth.